It seems pretty simple. There are a bunch of grey lines atop a white background with a dozen black dots on different intersection. The rub? You can't see all the dots at once, even though they really are all there.

Why can't we spot all 12 dots at the same time? According to Time, "This occurs because the eye’s stimulated light receptors can sometimes influence the ones next to them, creating illusions."

You'll either got mad or get a wicked headache looking at this grid too long. It joins a long list of mind-benders that have taken the good people of the interwebs for a mental ride. Remember this cylinder illusion? Or the brick wall one? What about this one about a red circle? And, then, of course, there was that whole matter of what color #thedress is.